October 7, 1998
QuestChat with Brent Nowlin

[ Oran/NASAChatHost
- 3 - 09:33:05 ]
Thank you for registering for the Turning Goals Into Reality/Aerospace
Team Online chat with Brent Nowlin from NASA Lewis Research Center. Be
sure you have read Brent's autobiography at http://quest.arc.nasa.gov/aero/team/nowlin.html
prior to joining this chat. This chat is scheduled to occur on Wednesday,
October 7 at 10:00 a.m. Pacific Time.

[ Susan/NASAChatHost
- 4 - 09:45:55 ]
Good Morning Everyone, This is your old pal Susan Lee! Oran is stuck in
another chat so it is my pleasure to host this chat with Brent Nowlin
until Oran can join us! Remember to read all the questions to check if
someone asks the questions you wanted to ask!! Also Read all of Brent's
answers they might give you a really good idea for a question!!

[ Deb-Mrs.Regal/YpsilantiCOPE - 6 - 10:00:38
]
Ypsilanti COPE is pleased to log on and have the pleasure of chatting
with Brent Nowlin.

[ BrentNowlin/LeRC
- 12 - 10:09:01 ]
Any jet plane uses a turbine engine as its means of propulsion. If a plane
has a propeller, it probably has what is known as a reciprocating engine,
which is somewhat similar to the engine used in automobiles (a lot larger,
with many modifications, of course!). There is now a hybrid engine called
a turboprop, which combines the turbine engine with a propellor to try
a use the higher power of the turbine engine, along with the good efficiency
of a propellor.

[ BrentNowlin/LeRC
- 14 - 10:13:11 ]
A typical workday is hard to define. Most of my days are pretty different
from each other! Usually I check my e-mail and phone messages first thing
in the morning. I then take care of anything that needs to be done in
the turbine testing facility. Work in the turbine facility may include
designing new systems, checking out systems, or simply operating the systems.
The facility is pretty complex and has a large number os invidual systems,
each system having a large number of individual pieces/parts. I then check
e-mail / voice mail again around lunch time, then I head back to the facility
for more of the same. Meetings that may be sheduled are also mixed in
there as well.

[ BrentNowlin/LeRC
- 18 - 10:16:50 ]
Dane, We test just the turbine portion of a gas turbine engine. The current
turbine has 2 stages, which means that it has 2 individual parts that
rotate. The turbine is about 24 inches across, from blade-tip to blade-tip.
It's designed to spin at around 8000 rpm (revolutions per minute), and
it generates 2000 horsepower. The turbine facility itself is designed
to be able to test turbines that spin up to 17,000 rpm and generate up
to 3000 horsepower. That's a lot of horses!

[ Susan/NASAChatHost
- 15 - 10:15:05 ]
Do you have any help running the facility Brent?

[ BrentNowlin/LeRC
- 20 - 10:26:08 ]
Susan, Yes, I have lots of help. There's another electrical engineer to
assist me, and we are in dire need of a mechanical engineer (our mechanical
engineer just transferred). Also, there are 2 mechanics, and an electronics
technician that help out. There are also a whole bunch of other people
that are available if needed (electricians, computer programmers, etc).
Even though most of the systems are automatic, a lot of people need to
be present to run the facility. Deb, Some of the modifications include
changing the blading of teh turbines. As you may or may not know, you
can think of a turbine as a kind of glorified windmill - it's a device
that converts the energy of moving air (or a liquid) into shaft power.
Usualy, the best way to improve efficiency is to improve blading. Researchers
also are experimenting with using higher temperatures of the air going
into the turbine. That helps boost power and efficiency, but it can also
damage the turbine (melt the blades). That would be bad! So, a lot of
time and research is being spent on ways to oversome the drawbacks of
all these issues. To answer your second question, our tests are not geared
specifically to increase the safety. Usually we are only interested in
making sure that no unsafe condition does happen in our facility. People
that are interested in increasing the safety have different facilities,
and are doing a lot of work in that area. But it's an area that has things
going on that we are just now beginning to understand and determine. It's
a developing science.

[ BrentNowlin/LeRC
- 24 - 10:31:09 ]RE: [Dane-Mrs.Regal/YpsilantiCOPE] What is
the size of the turbine used in an engine for a 747?
Dane, I don't know exactly what the size is for a 747 turbine. I can tell
you that, depending on the manufacturer of the engine, the size for a
one turbine section of a 777 engine is about 30 inches across, and the
other turbine section is about 60 inches across. I read that the inlet
to that engine is 120 inches across (that's 10 feet!). I mentioned two
sections because most large turbine engines have 2 separate turbine sections,
and high pressure turbine and a low pressure turbine.

[ BrentNowlin/LeRC
- 26 - 10:33:56 ]RE: [Dane-Mrs.Regal/YpsilantiCOPE] What different
kinds of fuels are used to power the turbines?
Dane, Teh fuel used to power turbine engines is Jet-A, although there
are a lot of other fuels being investigated. In our turbine facility,
we use natural gas to heat the air up before it enters the turbine. In
a real engine, the air entering the turbine section is very hot, so we
heat the air to simulate the air that the turbine would see in an actual
engine.

[ BrentNowlin/LeRC
- 28 - 10:40:56 ]RE: [Deb-Mrs.Regal/YpsilantiCOPE] When you
described the people necessary to operate the facility, you mentioned
computer programmers and earlier referred to your use of e-mail. What
roles do computers play in a testing facility such as yours?
Deb, You can't get away from computers anymore, even if you wanted to.
Most of the devices used in our facility are either computerized or are
used in computerized system. The data system, which measures and records
the data from the facility, has 1100 pieces of information that come from
the facility. Those pieces of information are things like temperatures,
pressures, flow rates, and other parameters of interest. Also, the facility
is controlled by something called a programmable logic controller. This
is a device that controls the facility systems, like how much air is flowing
through teh turbine, how much natural gas is being used (which determines
the temperature of teh air entering the turbine), the speed of the turbine,
and a lot of safety items. Also, we use computers with touchscreens as
interafces for the facility operators. Those touchscreens have programs
that the people use to open valves, turn pumps on, change the temperature,
and things like that. All of these systems are computerized, as well a
several that I haven't mentioned.

[ BrentNowlin/LeRC
- 30 - 10:44:32 ]RE: [Dane-Mrs.Regal/YpsilantiCOPE] How has
your work changed since you began your career?
Dane, Yes, my job has changed quite a bit. The basics haven't changed,
but the way we do things has. When I started 11 years ago, we still had
turbine testing facilities to run. But, most of the systems were either
manaully operated (run by people), or the controls were vaslty different.
Now, most of the systems are automated, and have changed quite a bit.
The mechanical aspects haven't changed as much, but some have changed.
Most of the newer technology comes in the electrical/computer area, which
is probably easy to see why.

[ BrentNowlin/LeRC
- 31 - 10:48:22 ]RE: [Dane-Mrs.Regal/YpsilantiCOPE] What kind
of communication do you have with people who design the other parts of
the turbine engines?
Dane, I also work in a compressor testing facility. The compressor section
of a gas turbine engine does kinda the opposite of the turbine section
- the compressor converts the energy of shaft power into the energy of
moving air. It's very interesting to see the interaction of teh turbine
and compressor sections. Changing the design of one may dramatically affect
the performance of the other. I work somewhat closely with the people
who design both the compressor section and the turbine section.

[ DaneandDeb-Mrs.Regal/YpsilantiCOPE - 34
- 10:56:24 ]
We need to log off soon. Thank you so much for your time and for your
interesting and informative answers!! The best to you in your work.

[ Susan/NASAChatHost
- 35 - 10:57:08 ]
Where does the time go? We're down to the last five minutes! Ypsilanti
thank you for your interesting questions, I learned a lot from reading
Brent's great answers! If you have time please let us know at the end
of the chat what you think of today's chat at http://quest.arc.nasa.gov/qchats/qchat-surveys.

[ BrentNowlin/LeRC
- 36 - 11:01:53 ]RE: [Deb-Mrs.Regal/YpsilantiCOPE] What you
wrote in your autobiography about the importance of integrity and ethics
in your career is inspiring. Can you give us some specific examples of
how the characteristics of diligence, honesty, and trustworthiness matter
even in the world of "hard science?"
Deb, I guess I don't exactly know what you mean by "hard science". I'll
interpret it to mean the world of applied science, that is, when people
put scienfic principals to work in everyday life. That's what engineering
is - applying scientific principals to solve a problem (as least, that's
my definition!). When it comes to diligence, an example I have there is
a system that a couple of us designed and built last year. It was a pretty
complex system. We had an old system that worked, but not very well. So,
we designed and built a new system. The system used parts made by several
manufacturers. Some of the parts didn't work the way the manufacturers
said they did (these are called "bugs"). We could have either abandoned
the idea, and used the old system, or we could have stuck to the plan,
found out ways around the bugs, and make it work. We chose to make it
work. We were successful, and the system is now fully developed for what
it was designed to do. The really great thing about that diligence is
that the system can be easily changed to do a whole lot of wother things,
as well. Honesty and trustworthiness are equally important. As a member
of a team, I have to trust my fellow team members. I have to not only
trust them to do their jobs, but also to help me out when I need them.
I also have to be honest with them - if I can't do something, I have to
tell them and we then find a different way. I find that honest is pretty
common in the engineering profession, more so than with some of the other
professions. In my job, though, we have to be honest with each other (and
ourselves!) because there is a lot of expensive, powerful machinery involved
in the day-to-day operation.

[ BrentNowlin/LeRC
- 37 - 11:04:12 ]RE: [Dane-Mrs.Regal/YpsilantiCOPE] What are
your future career plans?
Dane, My future career plans currently consist of staying here at Lewis
and investigating new things. I really enjoy building stuff - that's really
what I love to do. Fortunately, at Lewis, I have that opportunity to do
just that.

[ Susan/NASAChatHost
- 38 - 11:05:47 ]
Brent, Thank you so much for this opportunity to learn about turbine engine
engineering at Lewis Research Center. Your answers are terrific!

[ BrentNowlin/LeRC
- 40 - 11:09:50 ]RE: [DaneandDeb-Mrs.Regal/YpsilantiCOPE] Thank
you!!!
It was my pleasure. I wish you the best in your future educational endeavours
and hope that I have been helpful in answering your questions. Maybe our
paths will cross again in the future. Have a great year!